Method of cutting steel plates.



4 I PATENTED K0110, 1903. E. w, LEWIS & I. s. UNGER. METHOD OF CUTTINGSTEEL PLATES.

APPLIOAHON 11.21: my '19. 1903.

' N0 M DEL.

WITNESSES "wen-mas UNITED STATES Eatented November 16, 1963/ PATENTOFFICE;

METHOD OF'GUTTING STEEL PLATES.

SPECIFICATION forming part of Letters Patent No. 744,014, dated November10, 190

Application filed May 19, 1903.

To a whom it may concern.-

Be it known that we, EDWIN W. LEWIs and JOHN S. UNGER, of Munhall,Allegheny county, Pennsylvania, have invented a new and useful Method ofOuttingSteel Plates, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, formingpart of this specification, in which Figure 1 is a plan view showing oneform of apparatus arranged to carry out our invention, and Fig. 2 is aside elevation of the same.

Our invention relates to the sawing of steel plates, and moreparticularly to sawing the face portion of steel plates, such asarmorplate, having the glassy hard character imparted by carburizing andliquid-quenching. In some of the features, however, the method is notlimited to the sawing of face-hardened armor-plate, but relates to thesawing of any steel plate.

This application includes subjectmatter set forth in our previousapplications, Serial No. 137,156, filed December 30, 1902, Serial No.137,155, filed December 30, 1902, and Serial No. 72,823, filed August21, 1901.

In the art of finishing face-hardened armorplate the practice heretoforehas been to carburize the face portion by the Harvey process or anyother desirable method. The plate is then out to nearly the final shapeand size by slowly moving tools, such as planers; The plate, which isnow slightly larger than its final size, is then heated andwater-quenched,thus making the carburized face portion of a glassyhardness, and to finish the plate to the exact form desired it is turnedover with the hardened face down and is out with areciprocating orslow-movin g cutter through the softer back and down to the cemented andwater-quenched portion. This portion cannot be worked by any ordinarycutting-tool and in practice is cut away by the slow-grinding action ofan emery wheel. These two cutting operations, one before the waterquenching and one after the waterquenching, have been necessary, becauseno ordinary cutting-tool will act upon the glassy hard water-quenchedface portion, and hence this face portion is brought to nearly the finalSerial No- 157,767- (llo model.)

form before water-quenching and then finished to final form by grinding.The action of ordinary cutting-tools upon the carburized face is veryslow and difficult, even before water-quenching, and the expense offinislu ing the plates has been great.

. In finishing armorplate according to our invention the plate iscarburized on its face by the Harvey izing or other desirable method.

The plate is then forged in the usual manner, if desired, and thenheated and waterquenched without any previous'cutting. The

rough plate, with its carburized and waterhardened face, is then cut tothe desired form by the action of arevolving steel disk, which saws theplate to the desired size and shape. This revolving saw cuts throughboth the softer back and the glassy hard-face portion with comparativerapidity and does away with the necessity for any cutting of the platebefore water-quenching.

In the sawing of homogeneous steel plates it has been found that the sawclogged and stuck in the kerf after entering a short distance, thuspreventing successful sawing. We have found that this difficulty was dueto the pinching action on the saw of the piece being cut off and that wecan prevent such action by applying water to the cut-off portion in sucha way as to contract the piece being cut off and bend it away from thesaw.

In the drawings, in which we show one form of apparatus for carrying outour invention, 2 represents the saw; 3, the plate to be out, having thecemented and waterhardened face portion 4. v

5 is the moving table, carrying the plate.

6 is the strip or piece being out from the plate, and 7 designatesanozzle through which water is discharged against the strip or piecebeing cut from the plate.

7 In using the apparatus the table is fed progressively toward the sawin the direction of the length of the out, and the saw is revolved at arate of peripheral speed of preferably four or five miles per minute,though the speed may be varied, as desired. The binding of the saw inthe kerf is prevented by a stream of water directed against the piecebeing cut from the plate, thus causing it to bend outwardly andpreventing binding. It

Will be noticed that in the apparatus shown the chord of thecircumference of the saw at the sawing-point is less than the length ofthe plate being sawed.

The principal advantages of our invention consist in the great reductionin the cost of finishing, which results from doing away with thenecessity for the first step of cutting the plate beforewater-quenching.

The softer back of the plate may be cut by ordinary tools down to theface-hardened portion and the latter then cut off by our method. Theglassy hard-face portion may be produced by other methods, and manyvariations may be made in the form and arrangement of the sawingapparatus without departing from our invention.

lVe claim 1. The method of finishing armor-plate consisting incarburizing the face thereof, liquidquenching the carburized portion,and then cold-sawing through the plate by a rapidlyrevolving metal disk;substantially as described.

2. The method of finishing armor-plate consisting in carburizing theface thereof, reforging the plate, liquidquenching the carburized face,and then cold-sawing through the plate by a rapidly-revolving metaldisk; substantially as described.

3. The method of shaping armorplate having a glassy hard-face portion ofthe character imparted by carburizing and liquid-quenchin g, consistingin severing the face portion of the plate by passing a rapidly-revolvingcoldsaw through it, substantially as described.

4. The method of shaping armor-plate havin g a glassy hard-face portionofthe character imparted by carburizing and liquid-quenching, consistingin severing the face portion of the plate by applying arapidly-revolving cold-saw having the chord of its circumference at thesawing-point of less length than the plate, and passing it through theplate; substantially as described.

5. The method herein described of cutting steel plates,which consists inapplying to such plate a rapidly-revolving steel surface, passing italong and through the plate, and cooling the piece cut from the plate byapplication of a cooling fluid, and causing it thereby to curveoutwardly and afford clearance to the saw; substantially as described.

6. The method of finishing armor-plate consisting in carburizing theface, liquid-quenching the carburized portion, cold sawing through theplate, and supplying a cooling fluid to the strip or portion cut fromthe plate during sawing, to prevent binding of the saw inthe kerf;substantially as described.

In testimony whereof we have hereunto set our hands.

EDWVIN \V. LEXVIS. JOHN S. UNGER.

\Vitnesses:

L. M. REDMAN, II. M. OoRwIN.

